Systemic and Mucosal Immunogenicity of Monovalent XBB.1.5-Adapted COVID-19 mRNA Vaccines in Patients with Inflammatory Bowel Disease.

Recently updated COVID-19 mRNA vaccines encode the spike protein of the omicron subvariant XBB.1.5 and are recommended for patients with inflammatory bowel disease (IBD) on immunosuppressive treatment. Nonetheless, their immunogenicity in patients with IBD against rapidly expanding virus variants remains unknown. This prospective multicenter cohort study is the first study to investigate the immunogenicity of XBB.1.5-adapted vaccines in patients with IBD. Systemic and mucosal antibodies targeting the receptor-binding domains (RBDs) of the omicron subvariants XBB.1.5, EG.5.1, and BA.2.86, as well as their neutralization were quantified before and two to four weeks after vaccination with monovalent XBB.1.5-adapted mRNA vaccines. Vaccination increased levels of serum anti-RBD IgG targeting XBB.1.5, EG.5.1, and BA.2.86 (1.9-fold, 1.8-fold, and 2.6-fold, respectively) and enhanced corresponding neutralization responses (2.3-fold, 3.1-fold, and 3.5-fold, respectively). Following vaccination, anti-TNF-treated patients had reduced virus neutralization compared to patients on treatments with other cellular targets. 11.1% and 16.7% of patients lacked EG.5.1 and BA.2.86 neutralization, respectively; all these patients received anti-TNF treatment. At mucosal sites, vaccination induced variant-specific anti-RBD IgG but failed to induce RBD-targeting IgA. Our findings provide a basis for future vaccine recommendations while highlighting the importance of frequent booster vaccine adaptation and the need for mucosal vaccination strategies in patients with IBD.

Performance of two-dimensional shear wave elastography and transient elastography compared to liver biopsy for staging of liver fibrosis.

BACKGROUND: Staging of liver fibrosis traditionally relied on liver histology; however, transient elastography (TE) and more recently two-dimensional shear wave elastography (2D-SWE) evolved to noninvasive alternatives. Hence, we evaluated the diagnostic accuracy of 2D-SWE assessed by the Canon Aplio i800 ultrasound system using liver biopsy as reference and compared the performance to TE. METHODS: In total, 108 adult patients with chronic liver disease undergoing liver biopsy, 2D-SWE and TE were enrolled prospectively at the University Hospital Zurich. Diagnostic accuracies were evaluated using the area under the receiver operating characteristic (AUROC) analysis, and optimal cut-off values by Youden's index. RESULTS: Diagnostic accuracy of 2D-SWE was good for significant (≥F2; AUROC 85.2%, 95% confidence interval (95%CI):76.2-91.2%) as well as severe fibrosis (≥F3; AUROC 86.8%, 95%CI: 78.1-92.4%) and excellent for cirrhosis (AUROC 95.6%, 95%CI: 89.9-98.1%), compared to histology. TE performed equally well (significant fibrosis: 87.5%, 95%CI: 77.7-93.3%; severe fibrosis: 89.7%, 95%CI: 82.0-94.3%; cirrhosis: 96%, 95%CI: 90.4-98.4%), and accuracy was not statistically different to 2D-SWE. 2D-SWE optimal cut-off values were 6.5, 9.8 and 13.1 kPa for significant fibrosis, severe fibrosis and cirrhosis, respectively. CONCLUSIONS: Performance of 2D-SWE was good to excellent and well comparable with TE, supporting the application of this 2D-SWE system in the diagnostic workup of chronic liver disease.

Sca-1 is a marker for cell plasticity in murine pancreatic epithelial cells and induced by IFN-ß in vitro.

BACKGROUND & AIMS: Sca-1 is a surface marker for murine hematopoietic stem cells (HSCs) and type-I interferon is a key regulator for Lin-Sca-1+ HSCs expansion through Ifnar/Stat-1/Sca-1-signaling. In this study we aimed to characterize the role and regulation of Sca-1+ cells in pancreatic regeneration. METHODS: To characterize Sca-1 in vivo, immunohistochemistry and immunofluorescence staining of Sca-1 was conducted in normal pancreas, in cerulein-mediated acute pancreatitis, and in Kras-triggered cancerous lesions. Ifnar/Stat-1/Sca-1-signaling was studied in type-I IFN-treated epithelial explants of adult wildtype, Ifnar-/-, and Stat-1-/- mice. Sca-1 induction was analyzed by gene expression and FACS analysis. After isolation of pancreatic epithelial Lin-Sca-1+cells, pancreatosphere-formation and immunofluorescence-assays were carried out to investigate self-renewal and differentiation capabilities. RESULTS: Sca-1+ cells were located in periacinar and periductal spaces and showed an enrichment during cerulein-induced acute pancreatitis (23.2/100 µm2 ± 4.9 SEM) and in early inflammation-mediated carcinogenic lesions of the pancreas of KrasG12D mice (35.8/100 µm2 ± SEM 1.9) compared to controls (3.6/100 µm2 ± 1.3 SEM). Pancreatic Lin-Sca-1+ cells displayed a small population of 1.46% ± 0.12 SEM in FACS. In IFN-ß treated pancreatic epithelial explants, Sca-1 expression was increased, and Lin-Sca-1+ cells were enriched in vitro (from 1.49% ± 0.36 SEM to 3.85% ± 0.78 SEM). Lin-Sca-1+ cells showed a 12 to 51-fold higher capacity for clonal self-renewal compared to Lin-Sca-1- cells and generated cells express markers of the acinar and ductal compartment. CONCLUSIONS: Pancreatic Sca-1+ cells enriched during parenchymal damage showed a significant capacity for cell renewal and in vitro plasticity, suggesting that corresponding to the type I interferon-dependent regulation of Lin-Sca-1+ hematopoietic stem cells, pancreatic Sca-1+ cells also employ type-I-interferon for regulating progenitor-cell-homeostasis.

Loss of TLR3 and its downstream signaling accelerates acinar cell damage in the acute phase of pancreatitis.

BACKGROUND: Acute pancreatitis is accompanied by acinar cell damage releasing potential toll-like receptor 3 (TLR3) ligands. So far, TLR3 is known as a pattern recognition receptor in the immune signaling cascade triggering a type I interferon response. In addition, TLR3 signaling contributes to programmed cell death through the activation of caspase 8. However, the functional role of TLR3 and its downstream toll-like receptor adaptor molecule 1 (TICAM1) in the inflamed pancreas is unknown. METHODS: To uncover the role of TLR3 signaling in acute pancreatitis, we induced a cerulein-mediated pancreatitis in Tlr3 and Ticam1 knockout (KO) mice and in wildtype animals. The exocrine damage was determined by blood serum analysis and histological examination. Immunohistochemistry, gene expression and immunoblot analysis were conducted to study TLR3 function. RESULTS: After the induction of an acute pancreatitis, wildtype mice showed a high endosomal TLR3 expression in acinar cells. In comparison to wildtype and Ticam1 KO mice, Tlr3 KO mice exhibited the highest severity of pancreatitis with an increased NF-κB activation and elevated expression of the pro-inflammatory cytokines Il6 and Tnf, although the amount of infiltrating immune cells was unaffected. Additionally, we detected a strong elevation of acinar cell necrosis and reduced levels of cleaved caspase 8 in Tlr3 and Ticam1 KO mice. CONCLUSIONS: TLR3 and its downstream adaptor TICAM1 are important mediators of acinar cell damage in acute pancreatitis. They possess a critical role in programmed cell death and our data suggest that TLR3 signaling controls the onset and severity of acute pancreatitis.

[CME: Acquired Hemophagocytic Lymphohistiocytosis]. / CME: Sekundäre hämophagozytische Lymphohistiozytose.

CME: Acquired Hemophagocytic Lymphohistiocytosis Abstract. Acquired hemophagocytic lymphohistiocytosis comprises a heterogenous group of hyperinflammatory immunoreactions often resulting in uncontrolled immune responses, mainly throughout proliferation of cytotoxic T cells and hemophagocytosis by macrophages. Hemophagocytic lymphohistiocytosis is often underdiagnosed, contributing to its high morbidity and mortality. A systematic diagnostic approach and the use of established diagnostic criteria should lead to an early diagnosis, which is crucial for any therapeutic attempt to achieve a curative state of the disease.